FIG. 1 indicates an example of a wireless communication system including a relay node.
Referring to FIG. 1, a wireless communication system includes a base station, a relay node, and a user equipment.
The relay node (RN) indicates a node wirelessly relaying a signal transmitted from a source node to a destination node in a manner of receiving in the middle. The relay node can be considered in order for the user equipment to provide data throughput coverage improvement, group mobility, temporary network arrangement, throughput improvement in a cell boundary region and/or coverage within a new region.
The user equipment may be able to directly perform a communication with the base station or perform a communication with the base station in a manner of hopping twice via the relay node. For clarity, the user equipment directly performing the communication with the base station is called a macro-UE (M-UE) and the user equipment performing the communication with the relay node is called a relay-UE (R-UE) in the following description.
The relay node transmits the data received from the base station to the user equipment situated within a relay node region and may be then able to transmit a data received from the user equipment situated within the relay node region to the base station. For clarity, a radio link between the base station and the relay node is called a backhaul link in the following description. A link from the base station to the relay node is called a backhaul downlink and a link from the relay node to the base station is called a backhaul uplink. In particular, a radio link between the relay node and the user equipment is called an access link. A link from the relay node to the user equipment is called an access downlink and a link from the user equipment to the relay node is called an access uplink.